Abstract:
The area near Bratina Island was studied by examining scales (large and small) of variability (spatial and temporal) of nutrients and plant biomass on the McMurdo Ice Shelf (MIS) with an aim to examine the role of the abundant cyanobacterial biofilm communities in controlling the supply and demand of dissolved nitrogen. Special emphasis was placed on the assessment of cyanobacterial growth and ... nutrient uptake rates on the processes of N-fixation, nitrification and denitrification. Data collected for each scale of variability includes transects surveys (ice/soil/water, standing/flowing water, ice capped Y/N, depth, flow guaged, water; colour, temperature, conductivity, benthic mats; colour, length, thickness), water samples for pigment and biomass analysis and water nutrients, monitoring the freeze-thaw cycle of two ponds and changes in the plankton, chlorophyll a content, N and P concentrations in 6 study ponds, comparison of the planktonic component of 6 ponds including conductivity, dissolved inorganic carbon, chlorophyll a concentration, primary production, N and P concentrations, benthic core samples for assessment of algal abundance, and oxygen electrodes measured profiles of oxygen and photosynthesis respiration of mats and the diel changes in pond water temperature.